During the maintenance and assembly of large machinery (e.g., aircraft and the like), it is often necessary to move, lift, and rotate relatively heavy objects in order to place them in the correct position and orientation with respect to other components. In general, with reference to FIG. 1, an object 102 having a center-of-mass 106 must be moved from a position 110(a) to a position 110(b) such that it can be attached to a mating component 104. This repositioning generally requires a combination of lifting, translating, and rotating the object, which may be accomplished in any number of steps and in any number of ways. Various types of lift mechanisms are traditionally used for this purpose, including, for example, transmission jacks, trunnions, and other such devices.
Prior art lift mechanisms are unsatisfactory in a number of respects. For example, as it is often necessary to rotate the object into place, there is a risk that the object will pivot into an undesirable position, causing danger to the object as well as the individuals operating the mechanism. The object's center-of-mass may fall outside the base of the lift mechanism, for example, leading to tipping of the entire assembly.
Furthermore, prior art devices generally require three or four operators to move and hold the object in place, leading to inefficiencies during operation. Likewise, such devices are typically very large, and thus cannot be effectively used in tight spaces.
Accordingly, there is a need for a lift mechanism that is both safe and efficient, requiring a minimum number of individuals to operate, and allowing for a wide range of motion in a confined space.